| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing device in which suitable preload is always applied to a ball even when a component member of the bearing device expands due to temperature rising, of which the variation of resonance frequency and run-out hardly generate by the temperature variation, and rotation accuracy is high. SOLUTION: A plurality of balls 6a for a first row and a plurality of balls 6b for a second row are disposed between a shaft 1 and a cylindrical outer ring member 2 surrounding the shaft. A reduced diameter ring 8 made of the same material as the outer ring member or a material having the same extent of coefficient of linear expansion as the outer ring member is fitted by pressure with the outer periphery of the outer ring member between two rows of outer peripheral rolling grooves 5a and 5b for the first and second rows of balls formed in the inner peripheral surface of the outer ring member, thereby elastically deforming the outer ring member inward. Thus, a reduced diameter part 9 projecting inward is formed between the first and second outer peripheral rolling grooves of the outer ring member. |
